Fig 4: (A) Map view sketch of main erosional and water flow features at the Oroville Dam after overflow at the emergency spillway was stopped. 1 = area where crews started to work from February 13 to reinforce the partially damaged weir; 2 = erosion and bedrock incision downhill of the emergency spillway; 3 = zone of accumulation of debris from erosion and bedrock incision along main spillway, causing upstream blockage of the Feather River and interruption of functionality of the power station. Image by Shannon1, available at https://en.wikipedia.org/wiki/Oroville_Dam_crisis#/media/File:OROVILLE_DAM_5.svg (CC BY-SA 4.0); (B) View of channelized flow pattern diverting from damaged main spillway and confined to newly incised canyon. White arrow points to channelized incision created on February 12 by water outflow from the emergency spillway. Yellow arrow points to river bar consisting of debris accumulated from the erosion occurring at the main spillway. Photo by K. M. Grow, California Department of Water Resources, taken on February 26, 2017.